This invention relates to the initiation of electrical discharges and in particular to the initiation of such discharges in inert gas flows.
In the first of the above-mentioned related patent applications, there is disclosed a method and apparatus for establishing an electrical discharge from an electrode by forming a column of inert gas adjacent the electrode whereby the discharge is both long and directed. There is also disclosed an electrosurgical method and apparatus for coagulating by fulguration where a long electrical discharge is established either through a diffuse blanket of inert gas or a well defined column of the gas. Since the discharge is long, any tendency for the electrode to contact the surface being treated is substantially lessened whereby undesirable sticking of coagulated tissue to the electrode in electrosurgical applications is practically eliminated. However, there is some difficulty in initiating this long electrical discharge and thus, it is necessary to touch the electrode down on or very near to the tissue being coagulated. This can also result in adhesion of tissue to the hot electrode where the tissue can be ripped away when the instrument is removed from the site thereby causing surgical complications. Further, the adhered tissue tends to foul the electrode such that it must be scraped clean before the surgical procedure can continue.
In the second of the above-mentioned related patent applications, there is disclosed a method and apparatus for initiating the electrical discharge where an auxilliary source of charged particles is employed. In one embodiment an auxilliary electrical discharge in electrical series with the active electrode generates the charged particles. This arrangement is advantageous in that no external means are needed to generate the charged particles. However, all power from the gnerator to the patient must pass through the auxilliary gap and thus, there is some undesirable power loss.